Explore the vast range of titles available.

The spontaneous growth of tin whiskers has resisted interpretation for more than 70 years. Herein, tin whisker growth behaviours on Ti2SnC bulks cold-pressed under different pressures were studied. It was found that higher whisker growth propensity is reached when Ti2SnC cold-pressed under higher pressure. Several thicker whiskers with diameter more than 3 μm were observed on the samples formed under higher pressure, while the diameter of more than 50% whiskers ranges from 0.5 μm to 1.5 μm for all of the samples. An atomic motion mechanism, in which the element source supplying Sn whisker growth diffuse through the Sn atom layer in Ti2SnC lattice, and the interaction between Ti2SnC and Sn is considered to be the fundamental factor initiating the Sn whisker growth, was employed to understand the phenomena. The findings herein provide new clues to understand the tin whisker growth behaviors and modulable metal whisker fabrication.

The calcium carbonate whisker (CW) and basalt fiber are gaining popularity due to its enhanced mechanical properties in composites. Also, the short and long fibers provide bridging role and resistance against cracking from micro- to macro-scale, respectively. The usage of long and short hybrid basalt fiber along with addition of CW in cement-based composites is still a research gap. In this work, experimental behavior of CW basalt hybrid fiber reinforced mortar is considered with various content and length (3 mm, 6 mm, 12 mm, and 20 mm) of hybrid basalt fibers. In addition to this, synergy performance index is determined to quantitatively evaluate the positive interaction of hybrid basalt fiber in cementitious materials. The strengthening effect of whiskers and basalt fibers are also studied using scanning electron microscopy. The CW with various basalt fiber contents having different length of hybrid basalt fiber is used. It was found that the four various length of hybrid basalt fiber together with CW in cement mortar exhibited enhanced compressive, flexural, and split tensile strength than that of pure mortar and single length basalt fiber reinforced cementitious mortar. The results of synergy performance index showed similar trend with the experimental results. The strengthening effect caused by step by step crack arresting mechanism was also observed in cementitious material.

In this research the effect of adding silicon carbide nano whiskers (SiCw) into epoxy resin and the impact of reinforcing surface treated SiC wire-mesh (SiCwm) and woven aloevera/hemp/flax fibers (NF) were studied. The principal aim of this work was demonstrating the importance of adding SiCw (0.5 and 1.0 vol.%) and SiC wire-mesh with economical natural fibres (50 vol.%) and silane surface treatment on natural fibres in mechanical and low velocity impact behavior. The SiCw and natural fibres were surface treated by 3-Aminopropyltriethoxysilane whereas SiC wire-mesh was shot blasted. The composites were cured at room temperature using an aliphatic hardener Triethylenetetramine (TETA). The strength factor results showed that the silane surface modified composite designation ‘H 4 ’ gave highest normalized strength of 98%. The highest tensile and flexural strength of 141 and 240 MPa was observed for silane surface modified composite designation ‘H 4 ’. The low velocity impact damage behavior of ‘H 4 ’ composite designation showed higher resistance against to penetration. Transmission electron microscope (TEM) morphological images showed uniform dispersion of surface-modified SiCw in epoxy resin. Similarly the silane treated natural fibre and shot blasted SiC wire-mesh given improved adhesion with matrix. These high damping polymer composites offers their application in automobile, structural and domestic sector.

Lithium metal is considered the ultimate anode material for future rechargeable batteries1,2, but the development of Li metal-based rechargeable batteries has achieved only limited success due to uncontrollable Li dendrite growth3–7. In a broad class of all-solid-state Li batteries, one approach to suppress Li dendrite growth has been the use of mechanically stiff solid electrolytes8,9. However, Li dendrites still grow through them10,11. Resolving this issue requires a fundamental understanding of the growth and associated electro-chemo-mechanical behaviour of Li dendrites. Here, we report in situ growth observation and stress measurement of individual Li whiskers, the primary Li dendrite morphologies12. We combine an atomic force microscope with an environmental transmission electron microscope in a novel experimental set-up. At room temperature, a submicrometre whisker grows under an applied voltage (overpotential) against the atomic force microscope tip, generating a growth stress up to 130 MPa; this value is substantially higher than the stresses previously reported for bulk13 and micrometre-sized Li14. The measured yield strength of Li whiskers under pure mechanical loading reaches as high as 244 MPa. Our results provide quantitative benchmarks for the design of Li dendrite growth suppression strategies in all-solid-state batteries.Lithium whisker growth and mechanical properties can be studied in situ using a combination of two microscopies.

In order to study the effect of calcium sulfate whiskers and calcium carbonate whiskers on the road performance of asphalt mixtures, the high temperature stability, low temperature performance, and the change of water stability, the effect of two whiskers with different dosage levels on the road performance of asphalt mixture was obtained. The test results show that the calcium carbonate whiskers can improve the high temperature stability and water stability of the asphalt mixture within a certain dosage level range, but the low temperature performance has no obvious improvement effect, and adding excessive calcium carbonate whiskers will reduce the low temperature performance. The addition of calcium sulfate whiskers can significantly improve the road performance of the asphalt mixture. Under the same dosage level, the effect of calcium sulfate whiskers in improving road performance is better than that of calcium carbonate whiskers. When the content of calcium sulfate whisker is 0.4%, the road performance improvement effect of asphalt mixture is the best.

Lithium metal has the lowest standard electrochemical redox potential and very high theoretical specific capacity, making it the ultimate anode material for rechargeable batteries. However, its application in batteries has been impeded by the formation of Li whiskers, which consume the electrolyte, deplete active Li and may lead to short-circuit of the battery. Tackling these issues successfully is dependent on acquiring sufficient understanding of the formation mechanisms and growth of Li whiskers under the mechanical constraints of a separator. Here, by coupling an atomic force microscopy cantilever into a solid open-cell set-up in environmental transmission electron microscopy, we directly capture the nucleation and growth behaviour of Li whiskers under elastic constraint. We show that Li deposition is initiated by a sluggish nucleation of a single crystalline Li particle, with no preferential growth directions. Remarkably, we find that retarded surface transport of Li plays a decisive role in the subsequent deposition morphology. We then explore the validity of these findings in practical cells using a series of carbonate-poisoned ether-based electrolytes. Finally, we show that Li whiskers can yield, buckle, kink or stop growing under certain elastic constraints.

While cells within barrel cortex respond primarily to deflections of their principal whisker (PW), they also exhibit responses to non-principal, or adjacent, whiskers (AWs), albeit responses with diminished amplitudes and longer latencies. The origin of multiwhisker receptive fields of barrel cells remains a point of controversy within the experimental literature, with three contending possibilities: (i) barrel cells inherit their AW responses from the AW responses of thalamocortical (TC) cells within their aligned barreloid; (ii) the axons of TC cells within a barreloid ramify to innervate multiple barrels, rather than only terminating within their aligned barrel; (iii) lateral intracortical transmission between barrels conveys AW responsivity to barrel cells. In this work, we develop a detailed, biologically plausible model of multiple barrels in order to examine possibility (iii); in order to isolate the dynamics that possibility (iii) entails, we incorporate lateral connections between barrels while assuming that TC cells respond only to their PW and that TC cell axons are confined to their home barrel. We show that our model is capable of capturing a broad swath of experimental observations on multiwhisker receptive field dynamics within barrels, and we compare and contrast the dynamics of this model with model dynamics from prior work in which employ a similar general modeling strategy to examine possibility (i).

The evolution of internal compressive stress from the intermetallic compound (IMC) Cu6Sn5 growth is commonly acknowledged as the key inducement initiating the nucleation and growth of tin (Sn) whisker. This study investigates the effect of Sn-0.7Cu-0.05Ni on the nucleation and growth of Sn whisker under continuous mechanical stress induced. The Sn-0.7Cu-0.05Ni solder joint has a noticeable effect of suppression by diminishing the susceptibility of nucleation and growth of Sn whisker. By using a synchrotron micro X-ray fluorescence (µ-XRF) spectroscopy, it was found that a small amount of Ni alters the microstructure of Cu6Sn5 to form a (Cu,Ni)6Sn5 intermetallic layer. The morphology structure of the (Cu,Ni)6Sn5 interfacial intermetallic layer and Sn whisker growth were investigated by scanning electron microscope (SEM) in secondary and backscattered electron imaging mode, which showed that there is a strong correlation between the formation of Sn whisker and the composition of solder alloy. The thickness of the (Cu,Ni)6Sn5 IMC interfacial layer was relatively thinner and more refined, with a continuous fine scallop-shaped IMC interfacial layer, and consequently enhanced a greater incubation period for the nucleation and growth of the Sn whisker. These verification outcomes proposes a scientifically foundation to mitigate Sn whisker growth in lead-free solder joint.

Modern aero-engines need alloys that sustain both strength and ductility at high temperatures. However, conventional titanium alloys face inherent trade-offs between strength and ductility. In situ TiB-reinforced titanium matrix composites could fill this gap, but their texture evolution and hot-working mechanics are still poorly understood. In this study, TiB-reinforced IMI834 titanium matrix composites were synthesized using in situ technology in a remelting furnace. Meanwhile, the evolution of microstructure and texture in the hot-rolled titanium matrix composites was examined through both Abaqus simulations and experimental observations. Results indicate that dynamic recrystallization occurred in the microstructure of the composites at a deformation level of 95%. Due to the specific orientation relationship between the TiB whiskers and Ti matrix, the hot-rolled composites developed a pronounced [11-20]Ti // rolling direction fiber texture. TiB whiskers rotated toward the rolling direction, enhancing the intensity of the [11-20]Ti // rolling direction fiber texture, consistent with the predictions from numerical simulations. Tensile tests revealed that the combined effects of grain refinement and the rotation of TiB whiskers along the rolling direction increased the yield strength of the hot-rolled composite to 1153 MPa, while simultaneously raising the elongation to 10%.

High strength SiC whisker-reinforced Ti 3 SiC 2 composites (SiC w /Ti 3 SiC 2 ) with an improved thermal conductivity and mechanical properties were fabricated by spark plasma sintering. The bending strength of 10 wt% SiC w /Ti 3 SiC 2 was 635 MPa, which was approximately 50% higher than that of the monolithic Ti 3 SiC 2 (428 MPa). The Vickers hardness and thermal conductivity ( k ) also increased by 36% and 25%, respectively, from the monolithic Ti 3 SiC 2 by the incorporation of 10 wt% SiC w . This remarkable improvement both in mechanical and thermal properties was attributed to the fine-grained uniform composite microstructure along with the effects of incorporated SiC w . The SiC w /Ti 3 SiC 2 can be a feasible candidate for the in-core structural application in nuclear reactors due to the excellent mechanical and thermal properties.